Unhappy [Q] Deleted /system/bin/ files

Hello, i have thinkware T10Q tablet (at Turkey its name is general mobile e tab 4) ( http://www.thinkwareglobal.com/Eng/tablet_pc/index.asp ) . it is android 4.2.2

our school gave it us and there were some blocking apps for block to enter some sites or downloading some apps like facebook etc. And also developer setting, security settings were disabled. Anyway i took care of them problems. I rooted the tablet, deleted blocking apps etc. Everything was almos perfect. But still i cant access to some sites and all that i can access, there was certificate error. I took care of it with push certifacate. Certifacate errors gone but i cant still access some sites like facebook etc. And i tried lots of things, and

i deleted files of /system/bin/ accidentally . I can open only recovery mode and there is only factory reset setting. and also i think adb and fastboot work but not at recovery mode.

Is there any solution without sending warranty service?